1458P - Impact of 68Ga-FAPI-04 positron emission tomography/computed tomography (PET/CT) on staging and treatment in patients with gastric cancer

Background

⁶⁸Ga-labeled fibroblast activation protein inhibitor (FAPI) positron emission tomography (PET)/computed tomography (CT) has been shown to be advantageous in the detection of primary and metastatic lesions in many types of tumors, especially gastric cancer. However, there is a paucity of data on the value of 68Ga-FAPI-04 PET/CT for initial staging, recurrence detection after surgery and management of gastric cancer patients.

Methods

114 patients with gastric cancer who underwent contrast-enhanced CT and 68Ga-FAPI-04 PET/CT within one months were included. Two nuclear medicine physicians and a radiologist independently reviewed the imaging. TNM staging outcomes and subsequent treatment decisions were compared between contrast-enhanced CT and 68Ga-FAPI-04 PET/CT.

Results

84 patients underwent 68Ga-FAPI-04 PET/CT scans for initial staging, comprising 12 with stage II, 44 with stage III, and 28 with stage IV as per CT staging. Furthermore, 30 postoperative patients underwent PET-CT scanning in the presence of clinical symptoms, abnormal laboratory tests, and ambiguous CT findings. PET-CT revealed 29 newly metastatic lesions, with distant lymph nodes (12 occurrences) and peritoneal lesions (11 occurrences) being the most frequently observed. 68Ga-FAPI-04 PET/CT revised staging in 22/114 patients (19.3%). Among those, downstaging was recorded in 4/22 cases (18.2%) and upstaging in the remaining 18/22 (81.8%) patients. Overall, the findings of 68Ga-FAPI-04 PET/CT led to a change in clinical management in 15/114 patients (13.1%), including 12 instances of major and 3 instances of minor therapeutic changes. In 30 postoperative patients, 8 cases (26.3%) had recurrent metastasis, leading to 13.3% management change. Among 84 initial staging patients, 14 cases (16.7%) had staging change, resulting in 13.1% management change.

Conclusions

68Ga-FAPI-04 PET/CT proved to be a valuable tool for precise staging of gastric cancer patients. 68Ga-FAPI-04 PET/CT promises to improve conventional radiologic imaging methods for gastric cancer staging.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.